The People's Perspective on Medicine

Will L-Arginine Help Your Blood Pressure?

Nitric oxide can help keep blood pressure under control. Some evidence suggests that people who take l-arginine supplements make more nitric oxide.
Molecular structure of L-arginine (important amino acid) 3D rendering

If you’ve ever browsed the supplement shelves of your local health food store, you may have encountered l-arginine. This amino acid is found in proteins you may consume on a regular basis. Nuts and seeds, for example, are great sources of l-arginine. So are meats, poultry, fish, legumes like soybeans or chickpeas and seaweed. Do you also need to take it as a supplement? Such a recommendation is controversial.

Can L-Arginine Help the Heart?

Q. Dr. Louis Ignarro is a Distinguished Professor of Pharmacology at UCLA. He was awarded the Nobel Prize in Medicine in 1998 for his work on nitric oxide. He has written a book, No More Heart Disease, in which he describes the use of l-arginine, which is converted into nitric oxide in the body.

I was fortunate to attend pharmacy college with him at Columbia University. Several years ago, I called him to see if his research has changed. In response, he assured me that it has not.

I have been taking l-arginine for 10 years and my blood pressure is excellent. He told me he is taking it himself with similar results. (I am 78 years young.)

The Importance of Nitric Oxide:

A. Thank you for reminding us of Dr. Ignarro’s contributions. Nitric oxide is indeed important in controlling blood pressure. A number of natural substances such as beet juice and cocoa flavonoids act through this mechanism.

A placebo-controlled trial found that people who took a combination of l-arginine and B vitamins had more flexible blood vessels and lower blood pressure (European Journal of Nutrition, March 2018).  The daily dose was 2.4 g l-arginine, 3 mg vitamin B6, 0.4 mg folic acid and 2 mcg vitamin B12. The volunteers took this German product (Telcor Arginin plus) two tablets twice daily for three months.

They saw a modest drop in systolic blood pressure, about 6 mm Hg. Nonetheless, this change was statistically significant and comparable to the effect of many blood pressure medicines.

An earlier meta-analysis of 11 randomized controlled trials found a similar effect (American Heart Journal, Dec. 2011). In addition, l-arginine lowered systolic blood pressure by approximately 6 mm Hg in these studies as well. Doses ranged from 4 to 24 grams/day, considerably more than in the more recent German research.

Side Effects of L-Arginine Supplementation:

Before people embark on a daily supplement program, they should know the risks. While l-arginine is not toxic, it does have a few side effects. For one thing, individuals taking this supplement daily may develop insulin resistance (Life Sciences, Dec. 15, 2017).

L-arginine, taken as a supplement, can also increase inflammation in the presence of malaria infection (Tohoku Journal of Experimental Medicine, May 2015). People who suffer frequent cold sores often report that avoiding foods rich in l-arginine (and presumably supplements, too) help them heal faster. Many individuals find that doses of 10 grams or more result in digestive distress and diarrhea.

L-Citrulline Supplementation:

Some scientists recommend l-citrulline supplements instead of l-arginine (Nutrients, July 19, 2018). People who take l-citrulline absorb it better.

According to the scientists, 

“its supplementation is therefore more effective at increasing l-arginine levels and NO [nitric oxide] synthesis.”

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    About the Author
    Terry Graedon, PhD, is a medical anthropologist and co-host of The People’s Pharmacy radio show, co-author of The People’s Pharmacy syndicated newspaper columns and numerous books, and co-founder of The People’s Pharmacy website. Terry taught in the Duke University School of Nursing and was an adjunct assistant professor in the Department of Anthropology. She is a Fellow of the Society of Applied Anthropology. Terry is one of the country's leading authorities on the science behind folk remedies. .
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    • Menzel D et al, "L-Arginine and B vitamins improve endothelial function in subjects with mild to moderate blood pressure elevation." European Journal of Nutrition, March 2018. DOI: 10.1007/s00394-016-1342-6
    • Dong JY et al, "Effect of oral L-arginine supplementation on blood pressure: a meta-analysis of randomized, double-blind, placebo-controlled trials." American Heart Journal, Dec. 2011.
    • Salgueiro RB et al, "Exercise training reverses the negative effects of chronic L-arginine supplementation on insulin sensitivity." Life Sciences, Dec. 15, 2017. DOI: 10.1016/j.lfs.2017.10.001
    • Xu H et al, "L-arginine exacerbates experimental cerebral malaria by enhancing pro-inflammatory responses." Tohoku Journal of Experimental Medicine, May 2015. DOI: 10.1620/tjem.236.21
    • Allerton TD et al, "L-citrulline supplementation: Impact on cardiometabolic health." Nutrients, July 19, 2018. DOI: 10.3390/nu10070921
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    At 1.5 gm daily, I have not noticed a BP change. But a definite decrease in depression and increase in positive emotional energy

    My only concerns about l-arginine is the part about causing insulin resistance. How often is this reported? and can it be reversed if it should happen after taking l-arginine?

    I already take a daily dose of Vitamins B6 and B12. I will add folic acid and beet juice. I also take a prescribed Amlodipine Besylate (5MG tablet). The doctor prescribed another Amlodipine (?) (10 MG capsules). After just one day, that put me into a severe allergic reaction. I am back to the original Amlodipine Besylate. My BP is not that high (unless you ask me about my grand children.)

    Flora brand Beet Crystals is a tasty and easy to use form for your daily dose of beets. Just have to keep very dry. You can even eat right from the jar.

    I take L-Lysine when I eat any almonds to avoid cold sores. Do you know if taking it more regularly would balance out if I were to take L-Arginine? Does L-Citrulline have the same effect on cold sores as L-Arginine?

    I used L-Argentine for maybe a year and subsequently developed atrial fibrillation. Cause and effect? Maybe? You should read the warnings (they are stronger than cautions) on the label of the Whole Foods container before using L-Argentine.

    I too have contacted Dr. Louis Ignarro regarding L-Arginine. At his age he is amazing in what he does. My question was regarding the dosage of L-arginine.

    There is no doubt that taking this supplement makes a difference with my heart rate while performing similar exercise routines. My BP also is lowered when taking LA. Some of my research indicated the following:

    1: Large studies have been done regarding L-Arginine and ED which resulted in many (not all) success stories or where conditions were made better. Even Mayo Clinic mentions LA as a helpful remedy for ED

    2: The only negative of taking LA appears to be the lack of long term data regarding side effects on the human body. Some users say they have been on LA for over 20 years with no affects.

    3: Dosages that people take are all over the map. Some at 1 gm some at 2 gm and others at 5 gms daily. The 10 gms mentioned above is significantly higher than anything I’ve ever heard of.

    4: I’ve tried other recommended combinations of L-Arginine and pycnogenol or L-Citrulline and neither of these worked any better or worse than taking straight L-Arginine.

    5: I have noticed (and others have stated as much) that taking LA doesn’t appear to be as effective when taking it daily as taking it every other day. Don’t know why this is but I’ve noticed this many times over the years.

    Like I’ve said many times on this forum to me this is all about chemistry. As we grow old our bodies produce less and less of what is needed and therefore supplementation is necessary. I have had similar (and repeatable) positive effects with other supplements such as lutein and hyaluronic acid (and others).

    Can people with stage 4 chronic kidney disease take nitric oxide to help maintain their blood pressure?

    Nitric oxide is a gas, so nobody can take it directly. But you might be asking about taking supplements that boost NO production in the body. There does not seem to be a definitive answer to that question based on evidence, so we would suggest you refrain.

    My belief that we are all individuals, with our own chemical makeup, was confirmed in the past when I tried L-Arginine for my hypertension; it didn’t seem to have any effect. However, in my body’s particular chemistry, I have found that red beets and limes have a profound effect. I measure my pressures daily and have found that over consumption of either red beets or fresh squeezed lime juice can easily drive my pressures below recommended norms. For my beets, I use the Walmart brand sliced beets (haven’t tried the pickled variety) and put the entire contents of the can in a Magic Bullet. Four spoons of this slurry is the right amount for me.

    I’ve read Dr. Ignarro’s book about 5 years ago and started taking l-arginine in a dose of 1 gram. In taking my BP 1/2 hour later, I noted an almost immediate drop in both systolic and diastolic numbers. I was so delighted. I learned that the effect does not sustain lower BP over time however. So I increased l-arginine to three doses during the day, one gram each for a total of three grams, and kept my bedtime prescription of a beta blocker 12.5 mg for some time. Eventually, my readings were all so good, that I eliminated, with my doctor’s approval, my a.m. beta blocker and my good readings held throughout the day. From my looking into building up nitric oxide as we grow older, I think this is an important, well-researched supplement, as it “scrubs the arteries” and is said to help prevent heart attacks and stroke by keeping the arterial walls clean and flexible. I’m 79.

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